Managed Lapack Of Single.Hermitian Eigenvalue Decompose Method
Definition
Assembly: Numerics.NET.SinglePrecision (in Numerics.NET.SinglePrecision.dll) Version: 9.0.1
Overload List
Hermitian | Computes all eigenvalues and, optionally, eigenvectors of a complex Hermitian matrix A. |
Hermitian | Computes all eigenvalues and, optionally, eigenvectors of a complex Hermitian matrix A. |
Hermitian | Computes all eigenvalues and, optionally, eigenvectors of a complex Hermitian matrix A. |
HermitianEigenvalueDecompose(Char, MatrixTriangle, Int32, Span<Complex<Single>>, Int32, Span<Single>, Int32)
Computes all eigenvalues and, optionally, eigenvectors of a complex Hermitian matrix A.
public override void HermitianEigenvalueDecompose(
char jobz,
MatrixTriangle storedTriangle,
int n,
Span<Complex<float>> a,
int lda,
Span<float> w,
out int info
)
Parameters
- jobz Char
= 'N': Compute eigenvalues only; = 'V': Compute eigenvalues and eigenvectors.
- storedTriangle MatrixTriangle
- n Int32
The order of the matrix A. N >= 0.
- a Span<Complex<Single>>
A is TComplex array, dimension (LDA, N) On entry, the Hermitian matrix A. If UPLO = 'U', the leading N-by-N upper triangular part of A contains the upper triangular part of the matrix A. If UPLO = 'L', the leading N-by-N lower triangular part of A contains the lower triangular part of the matrix A. On exit, if JOBZ = 'V', then if INFO = 0, A contains the orthonormal eigenvectors of the matrix A. If JOBZ = 'N', then on exit the lower triangle (if UPLO='L') or the upper triangle (if UPLO='U') of A, including the diagonal, is destroyed.
- lda Int32
The leading dimension of the array A. LDA >= max(1,N).
- w Span<Single>
W is TReal array, dimension (N) If INFO = 0, the eigenvalues in ascending order.
- info Int32
= 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value > 0: if INFO = i and JOBZ = 'N', then the algorithm failed to converge; i off-diagonal elements of an intermediate tridiagonal form did not converge to zero; if INFO = i and JOBZ = 'V', then the algorithm failed to compute an eigenvalue while working on the sub-matrix lying in rows and columns INFO/(N+1) through mod(INFO,N+1).
Remarks
If eigenvectors are desired, it uses a divide and conquer algorithm. The divide and conquer algorithm makes very mild assumptions about floating point arithmetic. It will work on machines with a guard digit in add/subtract, or on those binary machines without guard digits which subtract like the Cray X-MP, Cray Y-MP, Cray C-90, or Cray-2. It could conceivably fail on hexadecimal or decimal machines without guard digits, but we know of none.
Further Details:
Modified description of INFO. Sven, 16 Feb 05.
Contributors:
Jeff Rutter, Computer Science Division, University of California at Berkeley, USA
Authors: Univ. of Tennessee, Univ. of California Berkeley, Univ. of Colorado Denver, NAG Ltd.
Date: November 2011